-The human population quadrupled during the 20th century, increasing from about 1.5 billion in 1900 to about 6.8 billion in 2009
-This explosive population growth reached a peak of 2.1% growth rate in the late 1960s, the most significant demographic process since the beginning of the industrial revolution.
-The world population is expected to reach 9.1 billion in 2050 and to be increasing by about 33 million persons annually at that time.
-The population growth of the 49 least developed countries is still the fastest growing in the world, at 2.3% per year.
-During 2010-2050, nine countries are expected to account for half of the world’s projected population increase: India, Pakistan, Nigeria, Ethiopia, the United States, the Democratic Republic of Congo, the United Republic of Tanzania, China andBangladesh, listed according to the size of their contribution to global population growth.
-Globally, life expectancy at birth is projected to rise from 68 years in 2005-2010 to 76 years in 2045-2050.
-In terms of annual averages, the major net receivers of international migrants during 2010-2050 are projected to be the United States, Canada, the United Kingdom, Spain, Italy, Germany, Australia and France.
-The number of cities of one million or larger was 76 in 1950, 522 in 1975, 1,122 in 2000, and is set to exceed 1,600 by 2015. Using current population projections to 2050, most of the forthcoming growth in population will be in cities, with poor countries having “to build the equivalent of a city of one million people each week for the next 45 years” (Cohen, 2005).
United Nations – Department of Economic and Social Affairs
Cohen, J.E. 2005. Human Population Grows Up. Scientific American Sept 2005: 48-55.
McNeely, J.A. and Mainka, S.A. 2009. Conservation for a New Era. IUCN, Gland, Switzerland. 220 pp.